1. Field of the Invention
This invention relates to a chord recognition system for an electronic musical instrument, especially an electronic organ. The chord recognition system is responsive to a combination of keys depressed on the chord section of the manual by the organist and provides output signals representing that the combination of keys forms a recognizable chord, the type of musical chord and the alphabetic designation of the chord or that the combination of keys does not form a recognizable chord. These output signals are applied to other organ circuits such as a visual chord display circuit.
While the present invention is described herein with reference to particular embodiments, it should be understood that the invention is not limited hereto. The chord recognition system of the present invention may be employed in a variety of forms, as one skilled in the art will recognize in light of the present disclosure.
2. Prior Art
Chord recognition systems are known in the electronic organ industry. Electronic organs commonly have keys arranged in one or more manuals and a separate clavier of pedals. In general, the organist plays the melody with the right hand upon the upper manual, the chord with the left hand upon the lower manual and a bass accompaniment upon the pedal clavier with the left foot. The left hand chord performance and the left foot bass are the accompaniments for the melody performance played with the right hand. The left hand chord accompaniment is usually played in consonance with the right hand melody and the left foot bass accompaniment is played at a selected rhythm pattern different than the left hand chord accompaniment.
The chord recognition devices common in electronic organs require the organist to play the notes of a chord in a specific sequence so that the recognition process operates correctly. Other chord recognition devices dedicate logic circuits to recognize certain musical note combinations representing specific alphabetic chords. The amount of logic circuits necessary to recognize a representative number of chords is extremely large and correspondingly costly. The limited number of chords recognized and the playing restrictions placed upon the organist are significant deficiencies of these systems.
An object of the present invention is to provide a chord recognition system for detecting normalized chord patterns corresponding to the keys depressed by the organist and for tracking the root note for recognizable chord patterns.
Another object is to provide a chord recognition system for recognizing normalized chord patterns including inversions and logically restricting pattern identification to eliminate conflicts in recognizable patterns.
Another object is to provide a chord recognition system for providing a signal output representing that a normalized chord pattern is recognized, the type of chord pattern and the alphabetic or root note for the recognized chord pattern.
Another object is to provide a chord recognition system for providing a signal output representing that the keys depressed by the organist do not form a recognizable chord pattern.
Yet another object is to provide a chord recognition system for providing chord related output signals for use in other organ circuits.
Other objects will be apparent from the following summary and detailed description.